Time-switch for electric circuits.



Patented Apr. 9, 1912.

F. W. SMITH.

TIME SWITGH FOB. ELEGTBIG GIRGUITS.

APPLICATION FILED ?113.15, 1911.

' l l l l l l lj 15 end of a predetermined time.

UNITED STATES PATENT OFFICE.

mm: w. SUITE, 01' mmm, NEW JEBSEY, ASSIGNOB '.l SUNDE ELECTBI corm, OI' NEW YORK, N. Y., A COBPOBATION OF NEW YORK. I

Loz a-708.

To all whom z't may concem.-

Be it known that I, FRANK W. SMITH, a citizen of the United States, and resident of Westfield, county of Union, and State of 5 New Jersey, have invented certain ne'w and useful Im rovements in .Timeswitches for Electric rcuits, of which the following is n s ecification.

n ublic libraries it is desirable that each electrc light, or each group o'f lights, shall be controlled by a time crcuit breaker or switch in order that should the person using the light fail to open'the light circuit said circuit will be automaticall It is the common experience in large public libraries .that the lights are left burning, with the resultant burning out of the lamps and waste of electric energy.

A time switch or circuit breaker for use in public libraries must o rate comparatively slowly for the reason t at it is. not desired to o en the circuit and extinguish the lights matically set in operation by the switch button or key used for closig the light circuit -in order that there will be no possibility of closing the light circuit without at the 3 same time setting the switch in operation.

These switches must also be simple 'and comact in construction in order that' they may Be placed in convenient position for operation. It is also 'necessary in`switches for use in libraries that they be 'so' constructed as to opera-te absolutely without noise. `It is manfest that a reat many of' these switches must be used and that if there be the slightest noise from each of them the 40 noise in the aggregate would be very an-' no ng. 4 v I v t is the main object'of this invention. to

provide a .time switch which' will in eve way satisfy the requirements of 'a switc' for use in public libraries.

I device arranged to secure a very slow operaw tion of the motor.

Another object of the invention is to provide the clock-work or spring motor with a rotatable retarding device and to immerse said retarding device in a yieldable, readily r m P ?mit? i Pate'ted Apr. 9, 1912. 'Ap lication area February s, a. V

opened at theort intervals; Such a time switch must. 25 also be so constructed that it willbe auto- 'r`nm swrrcn ron. nmcrnc cmcUrrs.

Serial Io; 6083&

displaceable material inclosed in a suitable casng so that said retarding device will rotate n said material, the size of therotatable retarding device and the density of the 'displaceable material being so pro rtioned as to secure the desired speed of v 'e motor.

Another object of the invention is to immerse the ro'tatable retarding device. in' a readily displaceable material' of such a hature that its density will not be varied"'to any appreciable degree byjevaporation or ordinary changes in temperature. The importance of this condition of the retarding material will be manifest. If the density of the retarding material should be varied to a material extent by evaporation or by change in temperature the motor would operate at' varia dered 'inoperative if the ret-arding material should be materially increased in density by either evaporation or a decrease in temper'a'ture. i v

There are other equally important' objets and advantages of the invention which will 'be fully hereinafter set forth.

` In the draw' p Figure 1 is a vertical sectoal 'view o the casing inclosing the switch Operating mechanism, said mechanism being shown in front elevation, and a lamp circuit being diagrammatically shown as connected to the swtch points; F ig. 2 a vertical sectional view 'of the switchcomplote, the Operating parts being shown in .side elevation; and Fg. 3 a front elevation of the circuit closing and switch setting button or key. p i

Referring to the various' 'parte by numer-` als, 1 designates the switch casin which is in the form of a box closed by a ontcover plate 2, said plate beingsecured in position n such manner as to secure an air' and v moisture-proof joint between said parts;

I Mounted in this box are two motor supporting-side plates'and to the upperend ofone of these plates is ri dly secured the switch-carrying plate`4 o slate or other suitable insulating. material.. To this plate are secured two Contacts 5 separated a 'suitle speeds and might be ren- I able distance from each other and to which are connected the terminals of a light circilit 7; the circle 8 diagrammatically representinga-lamp in said circuit. Pivoted on this switch plate is a switch lever 9 carry-' ing the switch contact plate 10 ad'apted to engage the contacts to complete the light circuit. This contact plote is insula'ted from the switch lever in' any suitable manner. The lower substantially horizontal arm 11 of the switch lever is provided with a laterally rojecting latch pm 12 which is ada ted to tie engaged and held by a spring latc 13 when the switch lever is raised to complete the lighting circuit. The lower end of the latch projects considerably below the latch pin on the switch lever and is adapted to be engaged and moved to release the switch lever, as will be hereinafter described.

Mounted in the motor supporting plates is a horizontal main Operating or driving shaft 14. This shaft carries near one of its ends and within the casin or box 1, a spiral spring, 14 in the nature of a clock spring, the inner end of said spring being connected to the shaft and the outer end thereof being connected to a stud or bar 15 connected rigidly to the side plates 3. Rigidly Secured to said driving shaft is a ratchet wheel 16 which is adapted to be engaged by a pawl 17 carried by a large drivng gear 18 loosely mounted on said shaft. Rigidly mounted on said shaft is a switch setting arm 19 which extends upwardly and is provided with a small antifriction Operating roller 20 which is adapted to engage the free end of the switch lever, and raise it to its closed position when the Operating shaft is moved in the proper direction. Carried by this switch setting arm is a latch releasing finger 21 which is in position to erigage the lower end of the latch 13 when' the switch setting arm returns to its normal inoperative or unset position. The large driving gear 18 meshes with a small pinion 22 on a counter shaft 23; this latter shaft carrying a large pinion 24: which in turn meshes with another small pinion 25 Secured to a retarder shaft 26. On the retarder shaft is arranged a rotating retarder 27, as a mixer or other device. This rotating device may be of any suitable shape and of any desired size, its shape and size being governed by conditions which will be hereinafter set forth. The retarder shaft and the counter shaft are preferably arranged below the main driving shaft, but, of course, they may be arranged in any suitable position.

To insure the switch Operating arm 19 passing fi-eely under the arm 11 of the switch lever when said arm is returning to its normal inoperative position, said switch Operating arm may be formed in two parts .hinged together as shown in Fig. 1, a light spring holding the roller carrying part 19 in its proper operative position to permit said part to yield sufliciently to permit the roller 20 to pass under the arm 11- when returning to its normal or inoperative position on the left hand side of the latch 13. The part 19 is formed with a shoulder at its innerend which' rests against a corresponding shoulder on the main part of the arm to prevent the said pivot portion turning on its pivot when the switch Operating arm is' thrown to the right to set the switch. The lower portion of the box 1 is liquidt-ight so that'it is adapted to contain a suitable liquid or semi-liquid material, a charging opening being provided at a suitable pont, said opening eing closed by a suitable screw plug 28.

Within the lower ortion of the switch inclosing casing I pre erably place a liquid or semi liquid which will not appreciably evaporate or vary its density at ordinary temperatures. Suflicient of this material is placed in the casing or box 1 to completely mmerse the retarding device so that said material must be displaced as said device is rotated. It is manifest that by properly proportioning the retarding device to the density of the retarding material in the box the motor may be permitted to operate at the desired slow speed, notwithstanding the fact that speed nultiplying power reducing gears are introduced between the power or main spring shaft and the retarder shaft. It is also manfest that by immersing or submerging the retarding device in a displaceable material said device will be so retarded and its operation will be so slow that it will be absolutely noiseless.

-I prefer to employ as a'retarding material, an oil which will remain of a constant density throughout considerable variations in temperature and which will very slowly evaporate. By 'providing sufiicient oil within the box to imnerse all of the intermeshing gears as well as the retarding device the device will be absolutely noiseless; will be thoroughly lubricated and will be kept in a constant operative condition.

It is manifest that any suitable soft displaceable retarding material may be used in the box or casing of the switch device; and it is also nanifest that if desired the retarding device or retarder alone may be inclosed in a box and immersed in a suitable displaceable retarding material. It is manifwt that it is not absolutely necessary that the Operating gears be immersed in the oil, although by arranging the apparatus as shown the oil luhricating the operative parts and securing a slow rotation of the retarder.

lt is clear that with the short train of speed multiplying gearing shown in the drawing the speed of the Operating shaft would not be retarded to any material extent by the retarder if it were free of the retarding material. On the projecting end of the Operating shaft is rigidly Secured a switch operatng button or key 29 by means of which said shaft may be rotated to Swing the switch setting arm to the right, as indserves the double purpose of i meral 20. This will set position, the latch 13 snapping underthe; latch pin 12 andretaining the switch in its- On the switch button is` a set. position. pointerand stop-arm 30' which is adapted 'to engage a stop pin 31 in the face: of the box closure, snidstop pin limiting the movement' of the switch button and consequently of-the lover-setting arm 19. This operation of theswitch button the button s releasedthe springrotates the shaft, which motion is transmitted through the gear-ing to the retarder as previously described. Thelatch releasing finger 21 engages the lower end ofthe latchand moves t away from the la-tchpin' onthe switch lever and permits saidleverto drop downwardly thereby breaking; the light circuit nt the contacts.

In the face of the coverplate is formeda: series of apertures32 into any one ofwhich. the stop pn 31 may be insertedto-vary the' time required for, the operation -ofthe switch.

Each of. these apertures is numbered, as

shown in Fig. 3 so thatif it be desired toset the switchto open the 'lightrcircuit atthe end of twenty minutes, sto pin.31is placed'in the aperture oppositet enumben 20, and so on throughout the series. A-permanentstop 33 is arranged to be engagedzby thestop arm.

30 after the latch has been releasedfromthe latch pin and the lamp circuit has been opened.

The ratchet wheel 16. is shown as provided;

with eight teeth. In the closure plate there are formed eight apertures 32 spaced equal distances apart and correspondin to the eight teeth on the ratchet wheel, T e object of this isto permit thedriving shaftto berotated' by means of' the switch Operatingbutton a distance equal to one of the ratchetteethor a multiple of' that distance. Ifthe switch-is tobe timed to open the light circuit at the end of 'tenminutes the' lmiting` stop is placed in the aperture. adjacent the numeral 10 'on the face plate. This will permit thedriving shaft to be rotated sii-tii`- ciently tomove the ratchet wheel aroundone tooth each time theswitch is operated; so that the spring will always be restored to its ori 'nal tension. by the operation of' the swtch button, themovement: of the sha-ft through .the switch button compensating for the unwinding movement. of the shaftunder the action of the spring. Ifthe switch isto be operated to openithe. light-.circuit at 'the end 'of twenty minutes the movablestop isplaced in the aperture 32 adjacentathenushaft to be rotated suflicently to passtwo of the ratchet teeth under; the loc g pawl;

This will-give a longer travelto the switch.

unwinding of the spring.

partially rotates the Operating shaft and tightens the spring thereon. When permit the driving switch ;the drivng'shaft will be rotated and Operating-arm, and, as'before, the movement of the switch button will com ensate for the t will thus be seen that. in every operation the driving shaft will be rotated sufliciently in setting the-switch to compensate. for the unwinding of the spri inoperating the motor. It is, therefore, :fier that: the motor spring will always be in operativ'econdition and cannot unwind, orrmdowm When the spring-is once set n o in that condtionthroughout the life of the switch apparatus.,

H a-ving, thus fullydescribed my invention what I' claimas new and desire to secure by Letters Patentrisz 1. A time switch comprisin aboxorcasing, acircuit closing switch t erein, a latch to hold said switch to maintain the circuit closed, a spring motor" insaid box, one end of the drivingshaftof said motor extending through said: box, asw-itch setting arm carried by the drivin shaftawithinthe box and adapted-tomove -t e switchto its locked position, when said shaft is-rotated to wind the spring thereon, a releasing finger carried by said armand adapted to release the latch when the driving shaft is rotated by the spring tension, a power reducing gear train 'connected to and operated by the driving shaft, a rotatable. retarding device o erated by said gear train acfilling of readly displaceable lubricating material in the box and submerging-the retarding device and permittng said device to rotate very slowly, a switch Operating button connected to the outer endsof the driving shaft, a stop for saidbutton to prevent the operation of the motor, and a stop to limit the' rotation of the button in its switch Operating movement.

2.' Atime switch co'mprising a circuit closing device, a latch to hold said device to maintain the circuit/closed, a spring motor including a driving shaft, and a power redicing gear train, aswitch setting arm car ried by the driving shaft and adapted to move the switch device -to its locked position when said shaft is rotated to wind the spring* thereon, a releasing finger operated by the motor to release the latch when the driving shaft is rotated b the spring tension, arotatable retarding vice operated by the gear train, a box inclosing said retarding device, a filling-of displac'eable'material in the box submergingthe retarding device and permitting said device to rotate very slowly, a switch operatin button connected to one end of the driving-saft, a stop adapted to be engaged by said button to hold the 'motor against operation, and an adjustable stop to limit the rotation of. the button in its switch Operating movement, whereby in' setting the the Operating spring wound thereon an amount equal to: the unwinding of said spring in returning the switch Operating button to the. permanent stop.

3. A time switch comprising a circuit closing switch, a latch to hold said switch to 'maintain the circuit closed,"a spring motor including a driving shaft, a driving spring connected at one end to said shaft and at :its other end to a permanent fixed art, a ratchet wheel' rigidly fixed to said s aft, a drivig gear loosely connected to said shaft and .aar rying a pawl engaging the ratchet wheel'of said shaft whereby the gear will be driven through said ratchet wheel, a pawl, a gear train operated through said driving gear, a retarding device operated by said gear train, a switch setting arm carried by the driving shaft and adapted to move the switch to its locked position when said shaft is rotated to -wind the spring thereon, a releasing device operated by the motor and adapted to release the latch when the driving shaft is rotated by the' spring tension, a switch Operating button connected to one end of the driving shaft, a permanent'stop adapted to be engaged by saidbutton to hold the motor inoperative but permitting the drivng shaft to be rotated by said button to set and lock the switch, an adjustable stop to limit the rotation of the button and the driving shaft in its switch Operating movement, said stop being so adjustable as to permit of the rotation of the driving shaft a distance equal to one ratchet tooth or a multiple of sa'id distance, whereby the rotation of the driving, shaft in setting the switch will wind the spring thereon sutliciently to compensate for the unwinding of the spring in returning the' motor to its normal inoperative position.

4. A time switch comprising a box or casing, a circuit closing switch therein, a latch to hold said switch to maintain the circuit closed a spring motor in said box and including a driving shaft, and a driving spring wound thereon, a ratchet wheel rigidly secured on said driving shaft, a driving gear loosely mounted on said driving shaft, a gear train operated by said driving gear, a retarding device operated by said gear train, a filling of lubricating material in the box and submerging the retarding device, a switch setting arm carried by the driving shaft, a releasing finger operated by the said shaft, a,` switch Operating button connected to one end of the driving shaft, a stop for said button to hold the motor inoperative, a series of apertures in the box corresponding in number to the teeth of the ratchet wheel on the .driving shaft and arranged equal distances apart around said driving shaft, and an adjustable stop adapted to be inserted in any one of said apertures, substantially as described for the purpose set forth.

5. A time switch comprising a circuit closing switch, a latch to hold said switch closed, a spring motor, a ratchet wheel fixed to the driving shaft of said motor, a driving gear loosely connected to said shaft, a pawl car` ried by said gear and engaging the ratchet wheel, a gear train operated through said driving gear, a retarding device operated by said gear train, means operated by the driving shaft to move the switch to its locked positon when said shaft is rotated to wind the spring thereon, a switch Operating button connected' to one end of .the driving shaft and an adjustable stop to limit the rotation of the button and the driving shaft in its switch Operating movement.

6. A time switch comprisin a circuit closing switch, a latch to hold sai switch closed, a spring motor, a ratchet wheelfixed to the driving shaft of said motor, a driving gear loosely connected to said shaft, a pawl carried by said gear and engaging the ratchet wheel, a gear train operated through said driving gear, a retarding device operated by said gear train, means operated by the driving shaft to move the switch to its locked position when said shaft is rotated to wind the spring thereon, a switch Operating button connected to one end of the driving shaft, a plate through which the motor driving shaft extends, a stop on said plate for said button to hold the motor inoperative, a series of apertures in the said plate corresponding in number to the teeth of the ratchet wheel on the driving shaft and arranged equal distances apart around said driving shaft, and an adjustable stop adapted to be inserted in any one of said apertu'es, substantially as described.

7. A time switch comprising a box or casing, a circuit closing switch therein, a latch to hold said switch to maintain the circuit closed, a spring motor in said box and including a driving shaft, and a driving spring wound thereon, a ratchet wheel rigidly secured on said driving shaft, a driving gear loosely mounted on said driving shaft, a gear train operated by said driving gear, a retarding device operated by said gear train, aswitch setting arm carried bythe driving shaft, a releasing finger operated by the said shaft, a switch Operating button connected to one end of the driving shaft, a stop for said button to hold the motor inoperative, a series of apertures in the box corresponding in number to the teeth of the ratchet wheel on the driving shaft and arranged equal distances apart around said driving shaft, and an adjustable stop adapted to be inserted in any one of said apertures, substantially as described for the purpose set forth.

8. A time switch comprising a circuit closing device a latch to hold said device to *maintain the circuit closed, a drive shaft, a

driving spring connected to said shaft, a

switch setting arm carried by said shaft and adapted to move the switch device to its locked position when the driving shaft is rotated against the spring tension, a releasing finger rotatable with said shaft and adapted to release the latch when the driving shaft is rotated by the said spring, a power rcducing gear train connected to and operated by the driving shaft, a retarding device operated by said gear train, a switch Operating button connected to one end of the driving shaft, a stop adapted to be engaged by said button to hold the motor against op eration, and an adjustable stop to limit the rotation ot' the switch Operating button in its switch Operating movement, whcreby in setting the switch the driving shaft will be rotated and the Operating spring wound thereon an amount equal to the unwnding of said spring in returning the switch Operating button to its permanent stop.

9. A time switch comprising a liquid receptacle, a circuit closing switch, a latch to hold said switch to maintain the circnit closed, a spring motor, a retarding devicc in r said liquicl receptacle and operatively connected to the motor, a readily displaceable lubrcating retarding and sounddeaclening liquid in the liquid rcceptacle and snbmerging the retarding device, and Operating means therefor, means `to sinnltaneonsly tighten the spring of the motor and move the switch to its closed position` means to limit the movement of the spring tightening means, means Operating when the spring is released to release the latch and thereby open the switch a predetermincd time after the spring is released, and means to stop the spring after the latch is released.

In testimony whereof I hereunto atx my signature in the presence of two witnesses.

FRANK W. SBITH.

lVtnesses JOHN AITKEN, WVM. R. DAVIs. 

